The present invention relates to a new and distinct cultivar of ×Heucherella and given the cultivar name of ‘Twilight’. ×Heucherella is in the family Saxifragaceae. ×Heucherella ‘Twilight’ originated from a controlled cross between Heuchera ‘Midnight Bayou’, U.S. Plant Pat. No. 21,858, as the seed parent, and massed selected proprietary Tiarella, as the pollen parent.
Compared to the seed parent Heuchera ‘Midnight Bayou’, the new variety has smaller leaves that are rosy silver to silver rather than purple to rose-purple.
Compared to the Tiarella parent, the new variety has leaves that are dark and silvered rather than green.
Compared to the closest variety ×Heucherella ‘Infinity’ PPAF, the new cultivar has leaves that are less cut and a habit that is neater, with fewer and shorter inflorescences. The new cultivar is more silvered.
This new ×Heucherella is distinguished by:                1. large, rose plum to silver leaves with prominent dark veins,        2. attractive short inflorescences with white flowers in the spring,        3. a large mounding plant habit,        4. grows equally well in full sun or filtered shade in the Pacific Northwest, and        5. excellent vigor.        
This new cultivar has been reproduced only by asexual propagation (division and tissue culture). Each of the progeny exhibits identical characteristics to the original plant. Asexual propagation by division and tissue culture using standard micropropagation techniques with terminal and lateral shoots, as done in Canby, Oreg., shows that the foregoing characteristics and distinctions come true to form and are established and transmitted through succeeding propagations. The present invention has not been evaluated under all possible environmental conditions. The phenotype may vary with variations in environment without a change in the genotype of the plant.